1*4882a593SmuzhiyunFrom dc92574c10f3e2516ec6445b88c5d584f40df4e5 Mon Sep 17 00:00:00 2001
2*4882a593SmuzhiyunFrom: Jay Berkenbilt <ejb@ql.org>
3*4882a593SmuzhiyunDate: Mon, 4 Jan 2021 11:55:28 -0500
4*4882a593SmuzhiyunSubject: [PATCH] Fix some pipelines to be safe if downstream write fails (fuzz
5*4882a593Smuzhiyun issue 28262)
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun[Retrieved (and updated to remove updates on ChangeLog and fuzz) from:
8*4882a593Smuzhiyunhttps://github.com/qpdf/qpdf/commit/dc92574c10f3e2516ec6445b88c5d584f40df4e5]
9*4882a593SmuzhiyunSigned-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
10*4882a593Smuzhiyun---
11*4882a593Smuzhiyun ChangeLog                     |   6 ++++++
12*4882a593Smuzhiyun fuzz/qpdf_extra/28262.fuzz    | Bin 0 -> 40395 bytes
13*4882a593Smuzhiyun libqpdf/Pl_AES_PDF.cc         |   2 +-
14*4882a593Smuzhiyun libqpdf/Pl_ASCII85Decoder.cc  |   7 +++++--
15*4882a593Smuzhiyun libqpdf/Pl_ASCIIHexDecoder.cc |   6 ++++--
16*4882a593Smuzhiyun libqpdf/Pl_Count.cc           |   2 +-
17*4882a593Smuzhiyun 6 files changed, 17 insertions(+), 6 deletions(-)
18*4882a593Smuzhiyun create mode 100644 fuzz/qpdf_extra/28262.fuzz
19*4882a593Smuzhiyun
20*4882a593Smuzhiyundiff --git a/libqpdf/Pl_AES_PDF.cc b/libqpdf/Pl_AES_PDF.cc
21*4882a593Smuzhiyunindex 18cf3a4d..2865f804 100644
22*4882a593Smuzhiyun--- a/libqpdf/Pl_AES_PDF.cc
23*4882a593Smuzhiyun+++ b/libqpdf/Pl_AES_PDF.cc
24*4882a593Smuzhiyun@@ -238,6 +238,6 @@ Pl_AES_PDF::flush(bool strip_padding)
25*4882a593Smuzhiyun 	    }
26*4882a593Smuzhiyun 	}
27*4882a593Smuzhiyun     }
28*4882a593Smuzhiyun-    getNext()->write(this->outbuf, bytes);
29*4882a593Smuzhiyun     this->offset = 0;
30*4882a593Smuzhiyun+    getNext()->write(this->outbuf, bytes);
31*4882a593Smuzhiyun }
32*4882a593Smuzhiyundiff --git a/libqpdf/Pl_ASCII85Decoder.cc b/libqpdf/Pl_ASCII85Decoder.cc
33*4882a593Smuzhiyunindex b8df3e87..9d9f6704 100644
34*4882a593Smuzhiyun--- a/libqpdf/Pl_ASCII85Decoder.cc
35*4882a593Smuzhiyun+++ b/libqpdf/Pl_ASCII85Decoder.cc
36*4882a593Smuzhiyun@@ -119,10 +119,13 @@ Pl_ASCII85Decoder::flush()
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun     QTC::TC("libtests", "Pl_ASCII85Decoder partial flush",
39*4882a593Smuzhiyun 	    (this->pos == 5) ? 0 : 1);
40*4882a593Smuzhiyun-    getNext()->write(outbuf, this->pos - 1);
41*4882a593Smuzhiyun-
42*4882a593Smuzhiyun+    // Reset before calling getNext()->write in case that throws an
43*4882a593Smuzhiyun+    // exception.
44*4882a593Smuzhiyun+    auto t = this->pos - 1;
45*4882a593Smuzhiyun     this->pos = 0;
46*4882a593Smuzhiyun     memset(this->inbuf, 117, 5);
47*4882a593Smuzhiyun+
48*4882a593Smuzhiyun+    getNext()->write(outbuf, t);
49*4882a593Smuzhiyun }
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun void
52*4882a593Smuzhiyundiff --git a/libqpdf/Pl_ASCIIHexDecoder.cc b/libqpdf/Pl_ASCIIHexDecoder.cc
53*4882a593Smuzhiyunindex f20a9769..7845268e 100644
54*4882a593Smuzhiyun--- a/libqpdf/Pl_ASCIIHexDecoder.cc
55*4882a593Smuzhiyun+++ b/libqpdf/Pl_ASCIIHexDecoder.cc
56*4882a593Smuzhiyun@@ -97,12 +97,14 @@ Pl_ASCIIHexDecoder::flush()
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun     QTC::TC("libtests", "Pl_ASCIIHexDecoder partial flush",
59*4882a593Smuzhiyun 	    (this->pos == 2) ? 0 : 1);
60*4882a593Smuzhiyun-    getNext()->write(&ch, 1);
61*4882a593Smuzhiyun-
62*4882a593Smuzhiyun+    // Reset before calling getNext()->write in case that throws an
63*4882a593Smuzhiyun+    // exception.
64*4882a593Smuzhiyun     this->pos = 0;
65*4882a593Smuzhiyun     this->inbuf[0] = '0';
66*4882a593Smuzhiyun     this->inbuf[1] = '0';
67*4882a593Smuzhiyun     this->inbuf[2] = '\0';
68*4882a593Smuzhiyun+
69*4882a593Smuzhiyun+    getNext()->write(&ch, 1);
70*4882a593Smuzhiyun }
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun void
73*4882a593Smuzhiyundiff --git a/libqpdf/Pl_Count.cc b/libqpdf/Pl_Count.cc
74*4882a593Smuzhiyunindex 8077092a..c35619b8 100644
75*4882a593Smuzhiyun--- a/libqpdf/Pl_Count.cc
76*4882a593Smuzhiyun+++ b/libqpdf/Pl_Count.cc
77*4882a593Smuzhiyun@@ -27,8 +27,8 @@ Pl_Count::write(unsigned char* buf, size_t len)
78*4882a593Smuzhiyun     if (len)
79*4882a593Smuzhiyun     {
80*4882a593Smuzhiyun 	this->m->count += QIntC::to_offset(len);
81*4882a593Smuzhiyun-	getNext()->write(buf, len);
82*4882a593Smuzhiyun 	this->m->last_char = buf[len - 1];
83*4882a593Smuzhiyun+	getNext()->write(buf, len);
84*4882a593Smuzhiyun     }
85*4882a593Smuzhiyun }
86*4882a593Smuzhiyun
87